• 교육녹색환경연구
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• 제9권2호
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• pp.1-8
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• 2010

This study is to present an engineering solution for the repair frequency and repair rates of a building. The existing data for the repair frequency and repair rates are used to draw the probability distribution for the generalized repair frequency and repair rate in a building. The suggested methodology can be widely used for most buildings to estimate the legal repair frequency and repair rates. Also, the methodology can be applied to resolve the risks on the maintenance costs in LC (Life Cycle) plans or LCC (Life Cycle Cost) analysis. As the future studies, there are the multiple regression analysis including the parameters on incurred costs and the decision methods on efficient repair and replacement.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.249-256
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• 1999

This study is intended to propose a systematic procedure for the development of the reliability-based seismic safety and cost-effective Performance criteria for design and upgrading of long span PC bridges. In the paper, a set of cost function models for life cycle cost analysis of bridges is proposed. The total life cycle cost functions consist of initial cost and direct/indirect damage costs considering repair/replacement costs, human losses and property damage costs, road user costs, and indirect regional economic losses. The damage costs are successfully expressed in terms of Park-Ang median global damage indices and damage probabilities. The proposed approach is successfully applied to model bridges in both regions of a moderate seismicity area like Seoul, Korea and a high one like Tokyo, Japan. It may be expected that the proposed approach can be effectively utilized for the development of cost-effective performance criteria for design and upgrading of various types of bridges as well as long span PC bridges.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.386-397
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• 2007

One major development in bridge life cycle cost analysis (LCCA) in recent years is to develop deterioration model for bridge components so that the times of repair/replacement throughout a component's life span can be properly determined. Taiwan also developed her own bridge LCCA model in 2003, integrating with the bridge inspection database in the local bridge management system (T-BMS). Under the framework of the local LCCA model, this study employs the reliability method in developing a deterioration model of bridge components. A component deteriorates through time in its reliability, which represents the probability of a component's condition index exceeds a user specified threshold. Model assumptions and rationale are described in the paper. The steps for applying the developed model are explained in detail. Results and findings are reported.

• 한국정밀공학회지
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• 제29권9호
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• pp.931-937
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• 2012

In this study, we assessed environmental impacts of compound humidifiers using environmental life cycle assessment and presented the ways to improvements in energy consumption of them. We found eco-design parameters and $CO_2$-eq emissions in each stage of raw material acquisition, manufacturing, transportation, use and disuse in life cycle of the compound humidifiers. The highest $CO_2$ emission is found to be in the stage of use among all stages of life cycle, which is mainly due to power consumption in thermal heating of heating coil for sterilization during humidification. The power consumption and $CO_2$ emission in the stage of use can be reduced to 1/4 and 1/3 at the highest estimate through improvement of sterilization method, respectively. We suggested the replacement of conventional thermal heating coil by ultra violet light-emitting diodes (UV-LED) for sterilization and then presented the experimental results on the sterilization effects of UV-LEDs.

• 대한물리치료과학회지
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• 제1권1호
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• pp.145-163
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• 1994

This study was done to determine differences in effect of postoperative pain control in patients receiving auricular electroacustimulation vs transcutaneous electrical nerve stimualtion following total knee replacement surgery. Thirty-one cases referred to physical therapy department after treated by total knee replacement surgery by orthopedic surgery department at the Pohang St. Mary's Hospital from January 1993 through June 1994. Of 31 total knee replacement cases, 13 cases were auricular electroacustimulation group, 11 cases were transcutaneous electrical nerve stimulation group, and 7 cases were control group. The results of the study summerized are as follows: Thirty-one total knee replacement cases(male in 12 cases, female in 19 cases), ranging in age from 34 to 61 years(mean${\pm}$SD=49.90 7.56) with diagnoses of degenerative arthritis(20 cases), rheumatoid arthritis(9 cases), and other(2 cases). In auricular electroacustimulation group, there was a significant change of pain intensity, unpleasantness, and active range of motion after treatment(p<0.01). In transcutaneous electrical nerve stimulation group, there was a significant change of pain intensity, unpleasantness, and active range of motion after treatment(p<0.01). In control group, did not show significant pre-posttreatment differences in pain intensity, unpleasantness, active range of motion(p>0.05). The mean change in pain intensity and unpleasantness, active range of motion from pretreatment baseline for the 3 groups. Auricular electroacustimulation group showed the large magnitude of increase in pain intensity and unpleasantness, active range of motion when compared to its own pretreatment cycle. Transcutaneous electrical nerve stimulation group showed small magnitude of increase in pain intensity and unpleasantness, active range of motion when compared to its own pretreatment cycle. No significant changes were observed in control group. Highly significant differences in pain intensity, unpleasantness, and active rage of motion were found using an ANOVA measures between treatment groups and control group(p<0.01). The squares correlation coefficients of pain and function measures pretreatment-posttreatment differences for each group. In treatment group, there was significant correlation between pain scale and function(p<0.001). In control group, there was no correlation between the pain scale and function (p>0.05). The continuous study is needd for many interesting issues of auricular electroacustimulation in new future.

• 한국터널지하공간학회 논문집
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• 제24권1호
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• pp.57-78
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• 2022

TBM의 굴착효율을 높이는 가장 중요한 인자인 디스크커터와 커터비트는 커터헤드 설계 및 시공 시 핵심요소로 지반조건에 맞는 디스크커터의 배치, 간격, 개수, 크기, 재질 등은 TBM 공사의 성패를 좌우한다. 또한, 디스크커터는 대표적인 소모성 부품으로 교체횟수에 대한 정확한 예측이 수반되지 않으면, 공사비는 물론 공사에 막대한 지장을 초래 할 수 있다. 이에 본 연구에서는 대구경 이수식 쉴드TBM 현장에 대하여 설계 시 산정된 디스크커터의 교체횟수와 실제 시공 시 발생한 디스크커터의 마모깊이 및 교체위치에 대하여 현장데이터를 분석하여 비교·연구하였다. 정량적인 비교를 위하여 일정한 굴진데이터를 나타내는 구간에서 지반에 따라 풍화토/풍화암, 연암, 경암으로 나누어 구분하였으며, 디스크커터의 위치에 따라 동심원의 궤적이 다르므로 위치에 따라 비교분석 하였다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.145-150
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• 2007

본 연구는 민간이 공공시설을 짓고 정부가 이를 임대해서 쓰는 민간투자방식인 BTL사업 가운데 학교시설에 대한 LCC 사례분석을 수행한 연구이다. 사업서류 작성지침에 따라 유지보수비 항목인 수선비 및 교체비에 대한 LCC산출서결과를 바탕으로 사례분석을 실시하였다. LCC 분석은 크게 두 가지 유형으로 분석하였으며 각 유형별로 임대기간인 20년 유지보수비와 수명주기인 65년 유지보수비에 대한 LCC를 분석하였다. LCC 분석결과 건축공종이 LCC의 약 50%이상의 구성비를 나타냈으며 기계, 전기, 토목 순으로 분석되었다. 또한 본 연구를 수행하면서 현행 학교 BTG 사업의 LCC 분석에서 나타나는 문제점 및 개선방안을 제시하였다.

• 센서학회지
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• 제30권2호
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• pp.109-113
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• 2021

In this study, an automated culture media replacement system was developed to analyze changes in the contraction characteristics of cardiomyocytes according to the state of the culture media. For the long-term storage of culture media, a Peltier refrigerator with a temperature of 5 to 8℃ was provided and a pH of 7.4 was maintained. The cell culture media of the cardiomyocytes was continuously replaced using interlocking pumps at a flow rate of 0.83 μl/h. The cardiomyocytes in which the culture media was replaced automatically demonstrated lower heartbeats per minute compared to samples in which there was no replacement. However, these cardiomyocytes moved more uniformly and produced greater displacement in one heartbeat cycle. It was observed that the sarcomere length of the cardiomyocytes increased due to the automated culture media replacement system. These cardiomyocytes were found to demonstrate better maturation compared to the control group. The maturation of cardiomyocytes was verified through staining images. The proposed automated culture media replacement system generates a uniform heart rate and improvements in contraction force. Based on the study, patient-specific drug toxicity assessments can be conducted using differentiated cardiomyocytes in induced pluripotent stem cells.

• Journal of the Korean Data and Information Science Society
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• 제22권4호
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• pp.775-784
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• 2011

본 논문에서는 비재생무료교체-수리보증이 종료된 이후의 수리가 가능한 시스템에 대한 주기적인 예방보전모형을 고려한다. 이러한 예방보전모형에 대하여 기대순환길이, 총기대비용 그리고 단위시간당 기대비용을 각각 유도하고자 한다. 또한 유도된 단위시간당 기대비용을 최소화하는 최적의 예방 보전주기와 예방보전횟수를 결정하는 방법에 대하여 자세히 설명한다. 끝으로 고장시간이 와이블분포를 따르는 경우에 최적의 주기적 예방보전정책을 결정하여 본다.

• The Journal of Korean Physical Therapy
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• 제36권1호
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• pp.27-32
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• 2024

Purpose: This study was conducted to verify the effect of applying a pressure biofeedback unit on walking ability and knee joint function while performing knee joint extensor strengthening exercises using resistance exercise equipment in total knee replacement (TKR) patients. Methods: This study was conducted on twelve patients receiving rehabilitation treatment after being admitted to a rehabilitation hospital post-TKR. Of these, six were allocated to a feedback group with a pressure biofeedback unit, and the other 6 were allocated to a control group without a pressure biofeedback unit. The subjects performed an exercise program for 45 minutes per session, five times a week, for two weeks. Walking ability and knee joint function were evaluated and analyzed before and after exercise. Results: The feedback group showed significantly better improvements in walking speed, gait cycle, step length on the non-operation side, time on the foot on the operation side, K-WOMAC stiffness, and K-WOMAC function than the control group (p<0.05). Conclusion: When strengthening the knee joint extensor muscles using resistance exercise equipment in TKR patients, the provision of a pressure biofeedback unit was found to improve walking ability and knee joint function by inducing concentric-eccentric contraction of the knee joint extensor muscles. Therefore, the study shows that exercise based on the provision of a pressure biofeedback unit should be considered when strengthening knee joint extensor muscles to improve the walking ability and knee joint function of TKR patients in clinical practice.